content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.operators;
  
  import io.reactivex.rxjava3.annotations.Experimental;
  import io.reactivex.rxjava3.core.Emitter;
  import io.reactivex.rxjava3.functions.Cancellable;
  
  /**
   * Provides an API on top of the {@link Emitter} signals that allow
   * setting and replacing a {@link Cancellable} resource to be cancelled
   * when the associated flow is cancelled.
   *
   * @param <T> the value type of the items emitted via {@link #onNext(Object)}.
   * @since 2.1.11 - experimental
   */
  @Experimental
  public interface FlowableAsyncEmitter<T> extends Emitter<T> {
  
      /**
       * Sets the current {@link Cancellable} resource to the provided one
       * and cancels the previous one if present.
       * <p>
       * If the underlying flow has been cancelled, the Cancellable
       * provided will be cancelled immediately before returning false.
       * @param c the new {@code Cancellable} to set
       * @return if true, the operation was successful, if false,
       *         the associated flow has been cancelled
       */
      boolean setCancellable(Cancellable c);
  
      /**
       * Sets the current {@link Cancellable} resource to the provided one.
       * <p>
       * If the underlying flow has been cancelled, the {@code Cancellable}
       * provided will be cancelled immediately before returning false.
       * <p>
       * Unlike {@link #setCancellable(Cancellable)}, the previous
       * {@code Cancellable} is not cancelled when returning false.
       * @param c the new {@code Cancellable} to set
       * @return if true, the operation was successful, if false,
       *         the associated flow has been cancelled
       */
      boolean replaceCancellable(Cancellable c);
  
      /**
       * Returns true if the associated flow has been cancelled.
       * @return true if the associated flow has been cancelled
       */
      boolean isCancelled();
  
      /**
       * The async logic may call this method to indicate the async
       * API invocation didn't produce any items but it hasn't ended
       * either, therefore, the generator can perform another
       * API invocation immediately.
       */
      void onNothing();
  }